---
id: 6196adc17f77a714d51485f2
title: 步骤 17
challengeType: 0
dashedName: step-17
---

# --description--

设置冰山元素的堆叠层级，使其显示在 `.ground` 元素后面。

# --hints--

应该使用 `z-index` 属性来设置堆叠层级。

```js
assert.notEmpty(new __helpers.CSSHelp(document).getStyle('.left-mountain')?.zIndex);
```

应该将 `z-index` 属性设置为 `2`。

```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.left-mountain')?.zIndex, '2');
```

不应该更改 `.ground` 元素的 `z-index`。

```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.ground')?.zIndex, '3');
```

# --seed--

## --seed-contents--

```html
<!DOCTYPE html>
<html lang="en">

  <head>
    <meta charset="UTF-8" />
    <link rel="stylesheet" href="./styles.css" />
    <title>Penguin</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  </head>

  <body>
    <div class="left-mountain"></div>
    <div class="penguin"></div>
    <div class="ground"></div>
  </body>
</html>
```

```css
body {
  background: linear-gradient(45deg, rgb(118, 201, 255), rgb(247, 255, 222));
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100vh;
  overflow: hidden;
}

--fcc-editable-region--
.left-mountain {
  width: 300px;
  height: 300px;
  background: linear-gradient(rgb(203, 241, 228), rgb(80, 183, 255));
  position: absolute;
  transform: skew(0deg, 44deg);

}
--fcc-editable-region--

.penguin {
  width: 300px;
  height: 300px;
  margin: auto;
  margin-top: 75px;
}

.ground {
  width: 100vw;
  height: 400px;
  background: linear-gradient(90deg, rgb(88, 175, 236), rgb(182, 255, 255));
  z-index: 3;
  position: absolute;
}
```
